表面增强拉曼光谱和电化学方法研究中性条件下咪唑对镍电极的缓蚀作用

利用表面增强拉曼光谱技术(SERS)研究了咪唑在镍电极表面的吸附机理和吸附方式，并分别比较了镍电极在加入咪唑前后溶液中的循环伏安曲线和极化曲线，计算了其缓蚀效率。结果表明，在镍电极表面，咪唑起到了较好的缓蚀效果;在研究电位区间内所得的SERS谱图中，面内振动峰占据了主导地位，咪唑是以垂直略带倾斜的方式吸附在镍电极表面的;而N—H面内弯曲振动峰(1 173 cm-1)的出现和pH值接近中性的研究体系证明了咪唑是以中性咪唑分子的形式存在;低波数区N—Ni伸缩振动峰(214 cm-1)的出现进一步验证了咪唑通过N原子与镍电极表面略带倾斜的吸附方式。

Surface-Enhanced Raman Spectra and Electrochemical Studies on the Inhibition of Nickel Corrosion by Imidazole

Surface-enhanced Raman scattering (SERS) spectrum of imidazole adsorbed on a nickel electrode in 0.1 mol x L(-1) KCl solution was investigated as a function of applied potential. The corrosion inhibition effects of imidazole on the nickel electrodes in 0.1 mol x L(-1) KCl solution were investigated by using both cyclic voltagram and Tafel plot. The results indicated that imidazole was adsorbed on Ni electrode with tilted or perpendicular orientation due to the maximum enhancement of the in-plane vibration modes. The appearance of the peak at 1,173 cm(-1) (i. e. NH deformation) further supported the adsorption of neutral imidazole molecules in a neutral solution. A low-wave number band appeared at 214 cm(-1) was assigned to the Ni-N stretch, considering the interaction between imidazole molecules and the metal surface via N-atom. The molecules had maximum adsorption at -1.3 V. At higher negative potentials, the adsorption decreased gradually, which resulted in weaker inhibition effect.